New Tools in the Water Technology Toolbox Swellable Organosilica Materials for

Reversible Extractions of Dissolved Organics and Metals

Paul L. Edmiston

College of Wooster

Contact Information: pedmiston@wooster.edu

ACS Fall Meeting 2012, Philadelphia, PA Ensuring the Sustainability of Critical Materials and Alternatives

High Volume Waste Streams, Very Little Attention

“The solution to pollution is dilution.” When something outlasts a certain degree of usefulness, we wish it to disappear. Since matter cannot be destroyed, a convenient disposal method is dilution. Two high volume waste streams that are hard to dilute due to volume, but may hold great resource potential: 1. Produced Water 2. Stormwater Runoff

Produced Water: Energy-Water Nexus

Produced water is the water from petroleum production. 800 billion gallons of produced water every year.

Current practice onshore: Reinjection Current Practice off-shore: Overboard

Average 10 water: 1 oil ratio Produced water contains: dissolved organics production chemicals NORMS organic acids metals ions salt

Oil Sand Production: Energy-Water Nexus

Steam assisted gravity drain (SAGD) water 300 million gallons per day by 2030.

How much organic in produced water?

Just considering dissolved hydrocarbon and BTEX ~ 250 ppm 250 ppm x 800 billion gallons = 250 million gal of gasoline eq. Enough gasoline to supply U.S. needs for 1 day.*

*U.S. Energy Administration http://www.eia.gov/tools/faqs/faq.cfm?id=23&t=10

How much organic in produced water?

Just considering dissolved hydrocarbon and BTEX ~ 250 ppm 250 ppm x 800 billion gallons = 250 million gal of gasoline eq. Enough gasoline to supply U.S. needs for 1 day.*

*U.S. Energy Administration http://www.eia.gov/tools/faqs/faq.cfm?id=23&t=10

Extraction of dissolved components has a substantial thermodynamic barrier. Need to overcome entropy.

Aryl-Bridged Mesoporous Silica That Swells: Osorb®

150 µm

Surface area: 400-600 m2/g Pore volume: 0.6-1.5 mL/g

200 nm

No solvent

+Solvent

Si OCH3

OCH3

OCH3

CH2CH2

CH2CH2Si

OCH3

OCH3

H3CO

Aerogels

Sol-Gel Derived Mesoporous Silicas

Sol-Gel Process

Ordered Templated Materials

Polysilsesquioxanes

200 nm200 nm 150 nm

Dry Partially Swollen Fully Swollen

200 nm200 nm 150 nm

Dry Partially Swollen Fully Swollen

Flexibly tethered array of silica nanoparticles

Gelation Crosslink Derivatize/Dry

Origin of Swelling Behavior

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Characteristics of Osorb

Surface Area and Pore Volumes of Various Osorb® Materials Swell Surface Pore Pore Size Distribution (%) Type mL/g Area(m2/g) Volume (mL/g) under 6 nm 6-8 nm 20-80 nm

1 5.2 885 2.85 6 8 68 2 9.8 416 0.57 48 22 - 3 4.6 171 0.27 98 - - 4 2.5 803 0.98 20 15 38

Force Generation Upon Swelling

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Organic liquids Hydrocarbon vapors

liquid = acetone

Max force 600 N/g (61,000 w/w) Work = 0.8 ± 0.1 J/g ΔHswell = 5.2 ± 1.2 J/g Entropically driven process 300% ΔV, 650% Δmass

Max 1x w/w change for condensable vapors when p=p0 13% volume,

propane

methane

Produced Water Trea tment

Os orb ® removes a wide range of organics from water:

Matrix tension

void volume new surface area

hydrophobic barrier

1

4 3

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Dissolved hydrocarbons

Continued matrix expansion

Absorption Model

Os orb ® ac ts as a “s olid s o lvent” tha t us es mechanica l re laxa tion as an additiona l driving force for abs orption of organics from water. Expansion is endothermic indicating a decrease in entropy (∆Smatrix) that is a significant energy term manifested by fact that swelling can produce mechanical forces that exceed 400N/g. In genera l, there is a one order of magnitude grea te r partition coeffic ient for abs orption by Os orb compared to liquid-liquid extrac tion due to the contribution from matrix expans ion.

k = Osorb/water equilibrium partition coefficient Kow = octanol-water partition coefficient

Conditions : contaminant concentration 100 ppm, 0.5% w/v Osorb per volume of solution, T=25°C.

Extrac tion of 30 Compounds by Os orb vs . logKow

Absorption Model: Solid Solvent

Pesticide waste Complex mixture of pesticides, dyes, BTEX, surfactants (5% organics by weight)

Treatment of Highly Impacted Water

Flow back water TOC before = 265 ppm TOC after = no detect 0.4%w/v Osorb

Rare Earth Extraction from Shale Gas Water

Rare earths elements are not rare, but formations of high concentration are hard to find. Found in alluvial deposits where freshwater meets salt water. Ideal location would be in ancient estuary environments. Many are buried in shale deposits. Hydraulic fracking is exploring deep shale deposits.

Utica shale shows regions where rare earth element concentrations are in excess of 4,000 ppm. Exploring synergistic extraction of REEs and hydrocarbons in PW

Rare Earth Extraction from Shale Gas Water

Challenge is extracting REE from Group II cations. Creating a type of Osorb that duplicates the multistage liquid-liquid extraction process use in conventional hydrometallurgical processes in a single core-shell particle Goals: 1) Rapid sampling system

using hand-held XRF

2) Larger scale extraction system for PW.

Funding from National Science Foundation and U.S. Department of Energy for pilot scale testing in the field, produced water and flow back

Trailer and Skid-Mounted Systems Available (4-60 gal/min) Skid system tested by Texas A&M University

Ex situ remediation: Produced water and flow back

Stormwater Runoff Problem

Stormwater Runoff Problem

What critical materials are being lost?

Nitrate and Phosphate

Woods J et al. Phil. Trans. R. Soc. B 2010;365:2991-3006

55% of the energy input in domestic wheat production is nitrate fertilizer Economical supplies of phosphate are

limited and can be depleted.

Rain Garden/Bioswale/Bioretention

Designed to slow the flow of stormwater and filter pollutants from the water before it eventually recharges ground water, seeps into the municipal storm sewer system, or discharge into waterways

Rain Garden, Bioswale, Bioretention System, Bioinfiltration System, Biofilter, Stormwater Wetland, Vegetated Buffer System

Multiple physical, chemical, and biological functions

Limited adsorption capacity: - Short retention time - Poor removal of soluble pollutants - Not recommended at “hot spots”

Rain Garden/Bioswale/Bioretention

Project Goals

Title: Development of Physico-Chemically and Biologically Activated Swelling Organosilica-Metal Composites Filter Media in Bioretention Systems for Enhanced Remediation of Urban and Agricultural Stormwater Runoff

Hypothesis: Properly amended Osorb-metal composites filter media in bioretention systems can remove a wide variety of stormwater runoff pollutants and significantly enhance overall treatment capacity of the systems

Work Plan: Develop Osorb-based materials with embedded reactive metal particles including aluminum (Al0), iron (Fe0), magnesium (Mg0), zinc (Zn0), and nickel (Ni0) to capture organic pollutants and chemically degrade pollutants from runoff water

Osorb®-Metal Composites

Al-Osorb Fe-Osorb Mg-Osorb Ni-Osorb Zn-Osorb

- Researched new metal-Osorb composites

- Examined reduction of motor oil, nitrate, phosphate, atrazine, estradiol, triclosan, and ethylene glycol

- Continue research to determine reduction mechanism and longevity in Phase II funding

Simulated Runoff Pollutants

Experimental Set-Up

A total of seven simulated runoff event once a week

Different contents (0%, 1%, 2%) of three Osorb-metals (Fe, Mg, and Zn) in soil base media: sand or soil mix

Column Tests:

Osorb®-Metal Composites Fill Media

Parameter Pollutants Concentration (mg/L Petrolum hydrocarbons Motor oil 1000 Nutrients Nitrate (NO3-N) 20 Phosphate (PO4-P) 10 Herbicide Atrazine (C8H14ClN5) 1 Pharmaceuticals 17α-Ethinylestradiol (C20H24O2) 1 Triclosan (C12H7Cl3O2) 1 Antifreeze/deicer Ethylene glycol (C2H6O2) 1000

1000 10 10 0.5 0.5 0.5

1000

Before

Before

After

After

OMR001&2 – Iron-Osorb Enviro-Swales (July 2012)

Iron-Osorb® Bioretention Systems

Field Tests: Iron-Osorb Enhanced Bioretention System

Site views of field-scale experimental bioretention systems (rain gardens) installed at the campus of the College of Wooster, OH. One is a standard model, and one version is enhanced with Iron-Osorb.

Column Tests: Motor Oil Removal

Improved removal efficiency of motor oil with Osorb-Metals

1000 mg/L of motor oil loading

Column Tests: Nitrate Removal

Up to 50% improved removal efficiency of NO3 with Osorb-Metals

10 mg/L of NO3-N loading

Column Tests: Phosphate Removal

66 Up to 40% improved removal efficiency of PO4 with Osorb-Metals

10 mg/L of PO4-P loading

Column Tests: Atrazine Removal

Up to 60% improved removal efficiency of atrazine with Osorb-Metals

500 µg/L of atrazine loading

Column Tests: Hormone Reduction

Field Tests:

Nutrient Removal

Lower effluent concentration of nutrients from iron-Osorb enhanced rain garden compared to standard rain garden

Column Tests: Soil Microbial Community

Scanning electron microscope (SEM) images of soil mix control (a) and Fe-Osorb amended soil mix (b) in the saturated bioretention design after the completion of 3-month column experiments. Blue arrows indicate bacteria or other microorganisms.

What is Next?

Currently developing a magnetically retrievable phosphate selective binding Osorb to amend agricultural bioswales for phosphate recovery and watershed protection.

Philadelphia is taking the lead!

Green City, Clean Waters Plan

Administrator Lisa Jackson and Mayor Michael Nutter announced April 10, 2012 that the EPA and Philadelphia will join in advancing the use of cutting-edge green infrastructure technologies to solve the city’s sewage overflows and create healthier neighborhoods for the city’s residents. The agreement specifically highlights Philadelphia’s capacity to serve as a model for cities nationwide to embrace green infrastructure to manage stormwater runoff.

Support: National Science Foundation U.S. Department of Energy Ohio EPA Collaborators: Dr. Hanbae Yang Dr. Tatiana Eliseeva Dr. Stephen Jolly Justin Keener Students: Zachary Harvey Alison Chin Noel Mellor Christine Kasprisin Melissa Morgan Paige Piper

www.absmaterials.com pedmiston@wooster.edu 330-234-7999

Acknowledgements and References

Edmiston, P. L.; Underwood, L. A. Absorption of Dissolved Organic Species from Water Using Organically Modified Silica that Swells. Separa tion and Purifica tion Technology 66, 532-540 (2009). Burkett, C. M.*; Underwood, L. A.*, Volzer, R. S.*; Baughman, J. A.*; Edmiston, P. L. Organic-Inorganic Hybrid Materials that Rapidly Swell in Non-Polar Liquids: Nanoscale Morphology and Swelling Mechanism. Chemis try of Materia ls 20, 1312-1321 (2008). Burkett, C. M.; Edmiston P. L.; Highly Swellable Sol-Gels Prepared by Chemical Modification of Silanol Groups Prior to Drying. J Non-Crys ta lline Solids ,351 , 3174-3178 (2005). Edmiston, P.L.; Campbell, D.P.; Gottfried, D.S.; Baughman, J.*; Timmers, M.M.* Detection of Trinitrotoluene in the Parts-per-Trillion Range Using Waveguide Interferometry, Sensor & Actua tors B. 143, 574-582 (2010).

Permeability to Organics vs. Water Vapor

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N2, 1 mL/min Propane + H2O(g)sat

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Osorb disk

8 mm

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Diffusion cell – Osorb separated flow cells